US3738119A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Head pressure operated suction throttling valve
Assignee: Motors Liquidation Co
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Filing: 1971-07-23
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Granted: 1973-06-12
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Expires: 1991-07-23
Abstract
Abstract Refrigerating apparatus for an automobile air conditioning system including a pressure responsive expansion valve which opens to admit refrigerant to the evaporator in response to decreasing evaporator pressure for maintaining the evaporator pressure above a minimum level to prevent frost accumulation. A flow restricting throttling valve which is normally open, moves toward a closed position in the evaporator outlet to maintain evaporator pressure when head pressure downstream from the condenser falls to a predetermined level. Because changes in head pressure are proportional to changes in ambient temperature, the restriction of the evaporator outlet with decreasing head pressure permits the system to be operated at lower ambient temperatures without evaporator pressures falling below the frost formation level.
Inventors
- 👤 C Scherer
- 👤 D Lawson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:37
CPC Classifications
F; F25; F25B; F25B47/00; F25B47/006
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
209 words
Refrigerating apparatus for an automobile air conditioning system comprising: an evaporator with an inlet and an outlet; a Refrigerant compressor with its inlet connected by a suction conduit to the evaporator outlet; a condenser with its inlet connected to the compressor outlet; and expansion valve with an inlet connected to the condenser outlet and an outlet connected to the inlet of the evaporator; said expansion valve having a refrigerant passage between its inlet and outlet for the passage of refrigerant from said condenser to said evaporator; a movable valve member coactive with said passage for controlling the supply of refrigerant introduced into the evaporator and opening when refrigerant pressure within the evaporator decreases to a predetermined level to supply refrigerant to the evaporator for maintaining the evaporator pressure above a minimum level to prevent frost accumulation upon the evaporator; refrigerant flow control valve means between said evaporator outlet and compressor inlet responsive to decreasing refrigerant pressure between said condenser outlet and said expansion valve passage which corresponds to operation of the system below predetermined ambient temperature to move the valve means toward a closed position to restrict the withdrawal of refrigerant from the evaporator through the suction conduit for maintaining refrigerant pressure in the evaporator above said minimum level.
Claim 2
Dependent Claim
209 words
Refrigerating apparatus for an automobile air conditioning system comprising: an evaporator with an inlet and an outlet; a Refrigerant compressor with its inlet connected by a suction conduit to the evaporator outlet; a condenser with its inlet connected to the compressor outlet; and expansion valve with an inlet connected to the condenser outlet and an outlet connected to the inlet of the evaporator; said expansion valve having a refrigerant passage between its inlet and outlet for the passage of refrigerant from said condenser to said evaporator; a movable valve member coactive with said passage for controlling the supply of refrigerant introduced into the evaporator and opening when refrigerant pressure within the evaporator decreases to a predetermined level to supply refrigerant to the evaporator for maintaining the evaporator pressure above a minimum level to prevent frost accumulation upon the evaporator; refrigerant flow control valve means between said evaporator outlet and compressor inlet responsive to decreasing refrigerant pressure between said condenser outlet and said expansion valve passage which corresponds to operation of the system below predetermined ambient temperature to move the valve means toward a closed position to restrict the withdrawal of refrigerant from the evaporator through the suction conduit for maintaining refrigerant pressure in the evaporator above said minimum level.
Claim 3
Dependent Claim
226 words
Refrigerating apparatus for an automobile air conditioning system comprising: an evaporator with an inlet and an outlet; a refrigerant compressor with its inlet connected by a suction conduit to the evaporator outlet; a condenser with its inlet connected to the compressor outlet; a refrigerant pressure responsive expansion valve with an inlet connected to the condenser outlet and an outlet connected to the inlet of the evaporator; said expansion valve having a refrigerant passage between its inlet and outlet for the passage of refrigerant from said condenser to said evaporator; a movable valve member coactive with said passage for controlling the supply of refrigerant introduced into the evaporator and opening in response to a decrease in refrigerant pressure within the evaporator to introduce refrigerant thereto for maintaining the evaporator pressure above a minimum level which prevents frost accumulation upon the evaporator; refrigerant flow control valve means between said evaporator outlet and compressor inlet to restrict the withdrawal of refrigerant from the evaporator by the compressor for maintaining refrigerant pressure in the evaporator above said minimum level; said flow restricting valve including a member movable from an open position toward a closed position in response to decreasing refrigerant pressures between said condenser outlet and said expansion valve passage to a value below a level corresponding to operation of the refrigerating system at ambient temperatures below a predetermined temperature.
Claim 4
Dependent Claim
226 words
Refrigerating apparatus for an automobile air conditioning system comprising: an evaporator with an inlet and an outlet; a refrigerant compressor with its inlet connected by a suction conduit to the evaporator outlet; a condenser with its inlet connected to the compressor outlet; a refrigerant pressure responsive expansion valve with an inlet connected to the condenser outlet and an outlet connected to the inlet of the evaporator; said expansion valve having a refrigerant passage between its inlet and outlet for the passage of refrigerant from said condenser to said evaporator; a movable valve member coactive with said passage for controlling the supply of refrigerant introduced into the evaporator and opening in response to a decrease in refrigerant pressure within the evaporator to introduce refrigerant thereto for maintaining the evaporator pressure above a minimum level which prevents frost accumulation upon the evaporator; refrigerant flow control valve means between said evaporator outlet and compressor inlet to restrict the withdrawal of refrigerant from the evaporator by the compressor for maintaining refrigerant pressure in the evaporator above said minimum level; said flow restricting valve including a member movable from an open position toward a closed position in response to decreasing refrigerant pressures between said condenser outlet and said expansion valve passage to a value below a level corresponding to operation of the refrigerating system at ambient temperatures below a predetermined temperature.
Claim 5
Dependent Claim
247 words
Refrigerating apparatus for an automobile air conditioning system comprising: an evaporator with an inlet and an outlet; a refrigerant compressor with its inlet connected by a suction conduit to the evaporator outlet; a condenser with its inlet connected to the compressor outlet; a refrigerant pressure responsive expansion valve with an inlet connected to the condenser outlet and an outlet connected to the inlet of the evaporator; said expansion valve having a refrigerant passage between its inlet and outlet for the passage of refrigerant from the condenser to said evaporator; a movable valve member coactive with said passage for controlling the supply of refrigerant introduced into the evaporator and said valve member opening in response to a decrease in refrigerant pressure within the evaporator to introduce refrigerant for maintaining the evaporator pressure above a minimum level which prevents frost accumulation upon the evaporator; refrigerant flow control valve means between said evaporator outlet and compressor inlet to restrict the withdrawal of refrigerant from the evaporator for maintaining refrigerant pressure in the evaporator above said minimum level; saiD flow restricting valve including a reciprocal valve member interconnected by a valve rod to a piston one side of which is exposed to refrigerant pressure between said condenser outlet and said expansion valve passage to cause said valve member to move toward a more closed position in response to decreasing refrigerant pressure to a value below a level corresponding to operation of the refrigerating system at ambient temperatures below a predetermined temperature.
Claim 6
Dependent Claim
247 words
Refrigerating apparatus for an automobile air conditioning system comprising: an evaporator with an inlet and an outlet; a refrigerant compressor with its inlet connected by a suction conduit to the evaporator outlet; a condenser with its inlet connected to the compressor outlet; a refrigerant pressure responsive expansion valve with an inlet connected to the condenser outlet and an outlet connected to the inlet of the evaporator; said expansion valve having a refrigerant passage between its inlet and outlet for the passage of refrigerant from the condenser to said evaporator; a movable valve member coactive with said passage for controlling the supply of refrigerant introduced into the evaporator and said valve member opening in response to a decrease in refrigerant pressure within the evaporator to introduce refrigerant for maintaining the evaporator pressure above a minimum level which prevents frost accumulation upon the evaporator; refrigerant flow control valve means between said evaporator outlet and compressor inlet to restrict the withdrawal of refrigerant from the evaporator for maintaining refrigerant pressure in the evaporator above said minimum level; saiD flow restricting valve including a reciprocal valve member interconnected by a valve rod to a piston one side of which is exposed to refrigerant pressure between said condenser outlet and said expansion valve passage to cause said valve member to move toward a more closed position in response to decreasing refrigerant pressure to a value below a level corresponding to operation of the refrigerating system at ambient temperatures below a predetermined temperature.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-11 | 1976-12-11 | 1977-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-11 | 1980-12-11 | 1981-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-11 | 1984-12-11 | 1985-06-12 | $7700.00 | Window Closed / Lapsed |